This invention relates to a thermoelectric refrigerating system for cooling electronic components located downhole in a deep well where the ambient temperatures are normally too high for proper operation of those components.
Electronic components, including instrumentation, are employed for measuring or logging various parameters and conditions downhole is deep wells, such as oil wells and geothermal wells which may have depths of over 10,000 feet. Extremely high ambient temperatures are usually encountered in those deep wells and unless the electronic components are cooled in some manner, proper operation thereof will not be obtained. In accordance with one previous arrangement for achieving cooling of electronic instrumentation in a deep well to monitor downhole conditions, a precooled large block of copper is placed in a vacuum insulated dewar flask (which is smaller to a thermos bottle) along with the electronic components and the dewar flask is then lowered downhole into the deep well to the level where the measurements are desired. For a limited time, generally about one-half hour, the pre-cooled copper block will maintain the temperature of the electronic components sufficiently low to permit the instruments to operate as required to measure the sensed downhole conditions. After the high ambient temperature heats up the copper block, the electronic components will no longer function properly and may even burn up and be destroyed by the high temperature environment.
In contrast, the uniquely constructed downhole thermoelectric refrigerator of the present invention ensures that the downhole electronic components will be cooled continuously and will operate properly as long as desired. Well monitoring or logging can be maintained at all times and the instrumentation will never be destroyed by the high ambient temperatures that exist downhole. Moreover, the invention features a novel thermoelectric cooler configuration which provides an expandable single stage or a multi-stage thermoelectric cooling system.